1. Filed of the Invention
The present invention relates to a device for removing fine particles consisting mainly of carbon from exhaust gas emitted by automobile diesel engines or the like.
2. Description of the Prior Art
Hitherto, there has been proposed such an exhaust gas cleaning device of the kind described as having a filter or a cyclone disposed in the exhaust system and adapted to collect fine particles mainly consisting of carbon particles. It has been also proposed to dispose the carbon particles separating means in the vicinity of an exhaust manifold so that the collected carbon particles are burned by the heat of the exhaust gas.
The exhaust gas cleaning device employing a filter has a drawback that the filter is liable to be clogged with carbon particles, while the device incorporating a cyclone cannot completely collect the carbon particles because the latter has light small size. In the exhaust gas cleaning system in which the collected carbon particles are burnt by the heat possessed by the exhaust gas, it is essential that the exhaust gas temperature be as high as 600.degree. C. In the normal running of automobiles around streets, however, there is almost no condition which would raise the exhaust gas temperature to such a high level as 600.degree. C. or higher. Therefore, the collected carbon particles are burned incompletely, causing clogging of the filter.